13 Jul
2004
13 Jul
'04
7 p.m.
On Tue, Jul 13, 2004 at 10:21:23 -0700, Joshua Haberman wrote:
Thats true, but that problem (running out of disk buffer) only happens in
extreme conditions, soft RT systems fail under lots of extreme conditions
awyway.
- Steve
Its not my
experieince that you usually need to allocate memory in RT
threads, the times when I've seen it done are mostly <generalisation>
bacuase of bad design, excessive OO-ness or lack of knowledge of
alloca(3) </generalisation>.
One reason I can think of is that you want to be sure to never, ever
drop a captured buffer when you are recording. You need buffers to send
the captured audio data to a disk thread, but without being able to call
malloc() from the audio thread, you have to pre-allocate a fixed amount
of memory for this purpose. No guess is high enough to guarantee that
you will never drop buffers, and the more you allocate in advance the
higher your overhead.